Currently, for the conventional “portable pressurized sprayers” disclosed such as US patent issued numbers U.S. Pat. Nos. 7,118,050 and 5,303,866 as well as Taiwan patent issued number 1253421, every structure for these foregoing conventional “portable pressurized sprayers” are almost similar. Referring to FIGS. 1 through 3, typical conventional portable pressurized sprayer comprises a water sprayer 1, a portable reservoir 2, a rechargeable battery 3 and a diaphragm compression pump 10, wherein said water sprayer 1 is a nozzle for spurting clean water out for cleaning target object, which is supplied from the portable reservoir 2 via a water intake hose 4, the diaphragm compression pump 10 and a water outtake hose 5; said portable reservoir 2, which colloquially called water tank, usually comprises a water replenish spout 21 on the top thereof for being supplied water, and a recessed planar base 22 with cross section in L-shape and consists of a horizontal planar bottom and a vertical right angle tucked buttress for conveniently accommodating the rechargeable battery 3 and a diaphragm compression pump 10 such that a water outlet 20 is disposed on the vertical tucked buttress of the recessed planar base 22; said rechargeable battery 3, which is 24 VDC for powering the diaphragm compression pump 10, can be recharged by means of a cigar-lighter power receptacle of automobile; and said diaphragm compression pump 10, which compresses and drive water from the portable reservoir 2 to the water sprayer 1 via the water intake hose 4, includes a water inlet 11 connected to the water intake hose 4 and a water outlet 12 connected to the water sprayer 1. Accordingly, the appealing function of the conventional portable pressurized sprayer is to breakthrough the confinement of the water supply so that it can be brought to outdoor anywhere to perform cleaning job as long as the portable reservoir 2 is beforehand fed sufficient water W via water replenish spout 21 (as shown in FIG. 2). Once the conventional portable pressurized sprayer is brought to the cleaning job site, upon power being turning on for activating the diaphragm compression pump 10, the water W in the portable reservoir 2 is sucked into the diaphragm compression pump 10 for being compressed into compressed water W′ orderly via water outlet 20 of the portable reservoir 2, water intake hose 4 and water inlet 11 of the diaphragm compression pump 10; Then, the compressed water W′ is expelled out to the water sprayer 1 for cleaning job orderly via water outlet 12 of the diaphragm compression pump 10 and the water outtake hose 5 (as shown in FIG. 3).
However, a drawback of “air residual in the water intake hose 4” exists in the foregoing operation of conventional portable pressurized sprayer that when the portable reservoir 2 is replenished with new sufficient water W if all the stored water W in the portable reservoir 2 has been used up. Because the water intake hose 4 directs the water W from the water outlet 20 of the portable reservoir 2 to the water inlet 11 of the diaphragm compression pump 10, the air residual in the water intake hose 4 will be mingled with water W and flowed into the diaphragm compression pump 10. The air residual, which is flowed into the diaphragm compression pump 10, becomes an improper load for all parts of the diaphragm compression pump 10 with malignant result not only harmfully affecting the stable compression but also incurring malfunction due to intermittently and unstably harsh impact on the output water pressure of the water outlet 12. Thereby, the service life of the diaphragm compression pump 10 will be shortened because the air residual therein as an improper load for all parts thereof.
Hence, having addressed to the issue of how to eliminating the foregoing “air residual in the water intake hose 4” during every replenishing water into the portable reservoir 2, the inventor of the present invention has actively undertaken research and development for a long time in experimental test. Eventually, an innovative solution is successfully worked out, and submitted a patent application in Taiwan with register number of 096142614 (publicized number of 200912139). Referring to FIGS. 4 and 5, the specific structure for the foregoing patent application to the China Patent Office comprises a cylindrical discharging mount 30 and a pneumatic hollow plunger 40, wherein said cylindrical discharging mount 30, which is a hollow cylinder, has a first cylindrical discharging chamber 31 and a second cylindrical discharging chamber 32 disposed in the lower section and upper section thereof in fluid communicable to each other such that the inner diameter of the first cylindrical discharging chamber 31 is bigger than that of the second cylindrical discharging chamber 32, a discharging vent 34 disposed in the central top thereof in facing towards the second cylindrical discharging chamber 32, and an air passage 33 disposed in the bottom wall thereof such that the first cylindrical discharging chamber 31 is fluid communicable with the water outlet 12 of the diaphragm compression pump 10; and said pneumatic hollow plunger 40, which is a bucket-like hollow piston, includes a top opening end 41, a bottom flanged hatch end 42, a backing compression spring 43, a side vent 44 and a sealing O-ring 45 of water-tight, wherein the opening end 41 is fittingly contained in the second cylindrical discharging chamber 32 in sliding manner while the flanged hatch end 42 is properly contained in the first cylindrical discharging chamber 31 in sliding manner with flange planar base thereof facing to the air passage 33 of the cylindrical discharging mount 30, the compression spring 43 is snugly inserted in the pneumatic hollow plunger 40 in facing to the opening end 41, the side vent 44 is created at the side wall of the pneumatic hollow plunger 40 near to the flanged hatch end 42 such that it is blocked if the pneumatic hollow plunger 40 is pushed backwardly all the way while it is able to pass fluid in the first cylindrical discharging chamber 31 if the pneumatic hollow plunger 40 is pushed forwardly all the way and the sealing O-ring 45 is placed around the peripheral of the pneumatic hollow plunger 40 in contact with the top rim of the flanged hatch end 42 (as shown in enlarged view of FIG. 5).
The operation modes for the foregoing patent application are demonstrated in FIGS. 6 and 7. In normal mode of no air A mingled in the compressed water W′, the pressure of the compressed water W′ in the water outlet 12 of the diaphragm compression pump 10 is higher than the resilient force of the compression spring 43 so that the flanged hatch end 42 of the pneumatic hollow plunger 40 is acted and pushed backwardly all the way by the pressure of the compressed water W′ at the air passage 33 of the cylindrical discharging mount 30, certain partial compressed water W′ in the water outlet 12 will flow into the first cylindrical discharging chamber 31 via air passage 33 and the pneumatic hollow plunger 40 will be pushed into the second cylindrical discharging chamber 32 all the way until the sealing O-ring 45 on the flanged hatch end 42 closely contact with distal inner end wall of the first cylindrical discharging chamber 31 in water-tight manner so that no compressed water W′ in the first cylindrical discharging chamber 31 can flow into the second cylindrical discharging chamber 32 and no more compressed water W′ in the water outlet 12 can further flow into the first cylindrical discharging chamber 31 via air passage 33. Thus, all the following compressed water W′ will normally flow out via water outlet 12 for proper purpose (as shown in solid line indicating arrowhead in FIG. 6). In abnormal mode with air A mingled in the compressed water W′, the pressure of the compressed water W′ in the water outlet 12 of the diaphragm compression pump 10 is lower than the resilient force of the compression spring 43 so that the flanged hatch end 42 of the pneumatic hollow plunger 40 is acted and pushed forwardly all the way by the resilient force of the compression spring 43 until the corrugated flange planar base of the flanged hatch end 42 contacts with proximal inner end wall of the first cylindrical discharging chamber 31 so that the side vent 44 at the side wall of the pneumatic hollow plunger 40 is moved in the first cylindrical discharging chamber 31 and able to pass fluid. Accordingly, the air A mingled in the compressed water W′ firstly will pass the corrugated flange planar base of the flanged hatch end 42 via the air passage 33 then flow into the first cylindrical discharging chamber 31; Secondly, the air A mingled in the compressed water W′ will flow into the pneumatic hollow plunger 40 via the side vent 44 now moved in the first cylindrical discharging chamber 31; And finally, the air A mingled in the compressed water W′ will be discharged out the diaphragm compression pump 10 orderly via the opening end 41 of the pneumatic hollow plunger 40 and the discharging vent 34 of he cylindrical discharging mount 30 to achieve the discharging effect for the air A mingled in the compressed water W′ (as shown in dashed line indicating arrowhead in FIG. 7). After all the air A mingled in the compressed water W′ have been discharged out of the diaphragm compression pump 10, the operation status is resumed to normal mode of no air A mingled in the compressed water W′ so that the pneumatic hollow plunger 40 in the cylindrical discharging mount 30 is again forced and pushed backwardly into the second cylindrical discharging chamber 32 as normal compression and discharging position (as shown in FIG. 6) to allow the diaphragm compression pump 10 being resumed to normal compression and discharging operation.
After mass production via molding process for the foregoing patent application in Taiwan with register number of 096142614, the discharging effect for the air A mingled in the compressed water W′ has been tested to achieve the expected efficiency satisfactorily. However, another drawback is found in the experimental test with circumstance as shown in FIG. 8. Before starting operation of the diaphragm compression pump 10, the flanged hatch end 42 of the pneumatic hollow plunger 40 will completely block the air passage 33 of the cylindrical discharging mount 30 under the resilience of the backing compression spring 43. At this moment, if any residual air A exists in the water intake hose 4, the compressed water W′ in the water outlet 12 will be mingled with certain air A to reduce the water pressure thereof when the diaphragm compression pump 10 is started so that the water pressure of the compressed water W′ is kept in less than the resilience of the backing compression spring 43. Thereby, the air A mingled in the compressed water W′ can never be smoothly discharged because the flanged hatch end 42 of the pneumatic hollow plunger 40 will be remained in completely blocking the air passage 33 of the cylindrical discharging mount 30 under the resilience of the backing compression spring 43 (as the hypothetical arrow heads shown at the air passage 33 in FIG. 8.). If this circumstance can not be remedied, it will become a new issue of the portable pressurized sprayer with malignant result in harmfully affecting efficiency of air discharging action therein. Accordingly, the inventor of the present invention must address to the new issue and contrive a further and thorough solution by the present invention.